Struktur Komposisi Dan Simpanan Karbon Di Sedimen Hutan Mangrove Pandansari, Kaliwlingi, Brebes

Abstract

Mangrove memiliki peranan penting baik secara fisik, ekonomi maupun ekologi. Salah satu fungsi ekologi tersebut adalah sebagai penyimpan karbon di alam. Upaya perlindungan dan pelestarian mangrove membutuhkan data sebagai acuan pembuatan kebijakan pengelolaan mangrove yang berkelanjutan. Tujuan penelitian ini untuk mengetahui komposisi dan struktur vegetasi mangrove serta mengetahui stok karbon sedimen di Hutan Mangrove Pandansari, Kabupaten Brebes. Penentuan lokasi ditetapkan berdasarkan tahun penanaman mangrove hasil program rehabilitasi, yaitu tahun penanaman 2005, 2008, 2011, 2014 dan 2017. Pengambilan data vegetasi dilakukan dengan metode purposive sampling dengan setiap stasiun dipasang plot berukuran 10 x 10 m. Pengambilan sampel sedimen karbon menggunakan bor gambut pada tiga kedalaman, yaitu 5 – 10 cm, 72,5 – 77,5 cm dan 197,5 – 202,5 cm.  Hasil penelitian menunjukkan bahwa di Hutan Mangrove Pandansari ditemukan tiga jenis mangrove, yaitu Rhizophora mucronata, Avicennia marina dan A. alba. Secara umum, vegetasi mangrove di lokasi penelitian memiliki nilai kerapatan >1.500 ind/ha yang didominasi oleh R. mucronata. Nilai Indeks Keanekaragaman (H’) dan Keseragaman (J’) mangrove di lokasi penelitian termasuk dalam kategori rendah. Stok karbon sedimen secara berturut-turut di stasiun 1 – 5 sebesar 1053,53 ton/ha, 747,63 ton/ha, 381,67 ton/ha, 612,11 ton/ha dan 798 ton/ha. Berdasarkan hasil tersebut, semakin tua usia pohon tidak mempengaruhi jumlah stok karbon yang disimpan di sedimen. Kedalaman 197,5–202,5 cm menjadi kedalaman yang paling banyak menyimpan karbon.

Mangrove is one type of dicotyledonous vegetation found in coastal areas, and is influenced by tides. Mangroves have an important role both physically, economically and ecologically. One of these ecological functions is to store carbon in nature. Efforts to protect and conserve mangroves require data as a reference for making sustainable mangrove management policies. This study aims to determine the composition and structure of mangrove vegetation and to determine the carbon stock of sediments in the Pandansari Mangrove Forest, Brebes. The research location was determined based on the year of planting of mangroves as a result of the rehabilitation program, namely the planting years of 2005, 2008, 2011, 2014 and 2017. Vegetation data was collected by purposive sampling method with each station installed a plot measuring 10 x 10 m. Carbon sediment samples were taken using peat drills at three depths, namely 5 – 10 cm, 72.5 – 77.5 cm and 197.5 – 202.5 cm. The results showed that in the Pandansari Mangrove Forest, three types of mangroves were found, namely Rhizophora mucronata, Avicennia marina and A. alba. In general, the mangrove vegetation at the study site had a density value of > 1,500 ind/ha which was dominated by R. mucronata. The value of the Diversity Index (H') and Uniformity (J') of the mangroves at the study site was included in the low category. Sedimentary carbon stocks at stations 2005, 2008, 2011, 2014 and 2017 were 1053.53 tons/ha, 747.63 tons/ha, 381.67 tons/ha, 612.11 tons/ha and 798 tons/ha, respectively. Based on these results, the older the tree age does not affect the amount of carbon stock stored in the sediment. The depth of 197.5–202.5 cm is the depth that stores the most carbon.